[PATCH 5.10 244/491] ASoC: fsl_easrc: Fix event generation in fsl_easrc_iec958_put_bits()

Greg Kroah-Hartman
2026-04-13T16:54:55Z

From: Mark Brown <broonie@kernel.org>

[ Upstream commit 54a86cf48eaa6d1ab5130d756b718775e81e1748 ]

ALSA controls should return 1 if the value in the control changed but the
control put operation fsl_easrc_iec958_put_bits() unconditionally returns
0, causing ALSA to not generate any change events. This is detected by
mixer-test with large numbers of messages in the form:

No event generated for Context 3 IEC958 CS5
Context 3 IEC958 CS5.0 orig 5224 read 5225, is_volatile 0

Add a suitable check.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://patch.msgid.link/20260205-asoc-fsl-easrc-fix-events-v1-1-39d4c766918b@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/fsl/fsl_easrc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sound/soc/fsl/fsl_easrc.c b/sound/soc/fsl/fsl_easrc.c
index 52b3f2d44f681..6af5c1735e2ed 100644
--- a/sound/soc/fsl/fsl_easrc.c
+++ b/sound/soc/fsl/fsl_easrc.c
@@ -52,10 +52,13 @@ static int fsl_easrc_iec958_put_bits(struct snd_kcontrol *kcontrol,
struct soc_mreg_control *mc =
(struct soc_mreg_control *)kcontrol->private_value;
unsigned int regval = ucontrol->value.integer.value[0];
+ int ret;
+
+ ret = (easrc_priv->bps_iec958[mc->regbase] != regval);

easrc_priv->bps_iec958[mc->regbase] = regval;

- return 0;
+ return ret;
}

static int fsl_easrc_iec958_get_bits(struct snd_kcontrol *kcontrol,
--
2.51.0